The present invention relates to a connector housing having a plurality of terminal receiving chambers, and more particularly to a connector housing of such a construction that undue displacement of a flexible lance, which would develop when releasing the retaining engagement of a connection terminal by a tool, can be prevented.
A terminal inserted into a connector housing is usually retained in a terminal receiving chamber or cavity in a double manner so as to positively prevent the terminal from slipping off from the rear of the connector housing.
In FIG. 7, a plurality of cavities 3 are formed in a connector housing la made of a synthetic resin or the like, and upper and lower cavities 3 vertically adjacent to each other are separated from each other by a partition wall (cavity floor) 5. A flexible lance 7 is provided in the cavity 3, and is integrally connected at its proximal end to the connector housing 1a, the other or distal end of the flexible lance 7 being free. The flexible lance 7 has a projection-like beak 9 formed at its distal end, which projects into the cavity 3.
A hole 11 for receiving the distal end of the elastically-deformed flexible lance 7 is formed through the cavity floor 5, as shown in FIGS. 8 and 9. Side beaks 13 are formed on opposite sides of the flexible lance 7, respectively, and each of these side beaks 13 has a vertical abutment surface at its front side, and a gently-slanting surface at its lower side.
A female terminal 15 to be inserted into the cavity 3 has an electrical contact portion 17 of a tubular shape formed at its front end, and a rear portion of this electrical contact portion 17 is a base portion 19. A retaining hole 21 is formed in that surface of the base portion 19 which faces the flexible lance 7, and the beak 9 is engageable in this retaining hole 21.
Retaining piece portions 23 are provided on opposite sides of the retaining hole 21, respectively, and these retaining piece portions 23 are formed by stamped-out portions produced when forming the retaining hole 21.
In this construction in which double retaining is effected by the flexible lance, when the terminal 15 is inserted into the cavity 3, the electrical contact portion 17 is brought into sliding contact with the beak 9 of the flexible lance 7, and presses the beak 9 so that the flexible lance 7 can be retracted into the hole 11 in the cavity floor 5. At this time, the side beaks 13 are displaced away from the cavity 3 beyond the retaining piece portions 23, and are held in this retracted position.
Then, when the retaining hole 21 in the terminal 15 reaches the beak 9, the flexible lance 7 is elastically restored, so that the beak 9 becomes engaged in the retaining hole 21, and also the abutment surfaces of the side beaks 13 are retained by rear edges of the retaining piece portions 23, respectively. Thus, double retaining of the terminal 15 is completed.
The terminal 15 received in the cavity 3 is often replaced by a new one, for example, because of defect or aged deterioration thereof. For effecting such replacement, a terminal removal tool 25 is inserted into the cavity 3 through an opening 27 disposed forwardly of the cavity 3 as shown in FIG. 10, and a removal operation is carried out. Then, the distal end portion of the flexible lance 7 is retracted into the hole 11 by the tool 25, thereby releasing the retaining engagement between the beak 9 and the retaining hole 21, as shown in FIG. 11.
However, if the flexible lance 7 is excessively displaced toward the hole 11 when the distal end portion of the flexible lance 7 is retracted into the hole 11, an undue stress exceeding its elastic deformation limit acts on the flexible lance 7, so that this lance may be plastically deformed. The flexible lance 7 once plastically deformed will not be restored into its original retaining position, and the retaining strength, obtained when the terminal 15 is again inserted into the cavity, is lowered. Thus, there is encountered a problem that the connector housing can not be re-used depending on the degree of deformation, which is quite uneconomical.